Remove limits on the magnitude of precision and width value in the
format specifiers of the sqlite3_mprintf() family of string rendering
routines.

Fix a bug that prevent ALTER TABLE ... RENAME from working
on some virtual tables in a database with a UTF16 encoding.

Fix a bug in ASCII-to-float conversion that causes slow performance and
incorrect results when converting numbers with ridiculously large exponents.

Fix a bug that causes incorrect results in aggregate queries that use
multiple aggregate functions whose arguments contain complicated expressions
that differ only in the case of string literals contained within those
expressions.

Fix a bug that prevented the page_count and quick_check pragmas from
working correctly if their names were capitalized.